Engine skip?

My wife’s 1995 pristine RMS stock with 110,000 miles has a slight what appears to be a skip with the engine that is intermittent but frequent. Going down the interstate on cruise control there is a barely noticeable momentary loss of power that lasts less than half a second but happens every 20 seconds or so. Other than that it runs great. It also happens when not using cruise. Any help is appreciated.

could be several things... possibly the torque converter locking/unlocking. maybe bad sparkplug(s) or wires or cap and rotor.

Check the water pump coolant temperature sensor harness connector for corrosion.  That input is (sadly) not filtered for transients, and an occasional corrosion-related open circuit will tell the PCM that the coolant is at -40F, radically changing fuel and spark, and unlocking the torque converter. If you have an [You must be registered and logged in to see this link.], you can use eehack to datalog and watch the inputs for any goofy transients. That's how I found this issue.

You guys are wizards! Thank you very much.

I had the sensor completely suddenly fail once. Car cut out and refused to start, ECM thought it was -40 outside and was flooding the engine. Replaced and  started right up. Might be worth keeping a spare. An ohmmeter test will show its bad.
AND I think you can UNPLUG the sensor and ECM will default to more normal temps and car will run ok again.

sherlock9c1 wrote:

Check the water pump coolant temperature sensor harness connector for corrosion.  That input is (sadly) not filtered for transients, and an occasional corrosion-related open circuit will tell the PCM that the coolant is at -40F, radically changing fuel and spark, and unlocking the torque converter.  If you have an [You must be registered and logged in to see this link.], you can use eehack to datalog and watch the inputs for any goofy transients. That's how I found this issue.

I checked the sensor. It was corroded. I unplugged and plugged it several times and sprayed some Amsoil MP on it and the problem resolved. I got a new one from Rockauto and will install it.

Thank you very much!

Many come with a new plug & pigtails too. If you don't replace the plug, be sure to clean the mating plug/terminals very well else the remaining coolant in the plug will give you the same problem again.

I bought the wrong one. Does anyone have a link to the right part on rockauto?

Thanks